The opening of right atrium into right ventricle is guarded by–

Correct option is B

Sol. The tricuspid valve separates the right atrium from the right ventricle and ensures one-way blood flow from the atrium into the ventricle. It has three cusps or flaps and prevents the backflow of blood during ventricular contraction (systole). Proper functioning of this valve is essential for maintaining effective cardiac circulation and avoiding right-sided heart failure.
Explanation of each option:
· (a) Mitral valve – Incorrect. The mitral (or bicuspid) valve is located between the left atrium and left ventricle, not the right side of the heart.
· (b) Tricuspid valve – Correct. It regulates blood flow from the right atrium to the right ventricle and prevents backflow during contraction.
· (c) Bicuspid valve – Incorrect. Another name for the mitral valve, which lies on the left side of the heart. It is unrelated to the right atrium or ventricle.
· (d) Aortic semilunar valve – Incorrect. This valve controls blood flow from the left ventricle to the aorta and is not located between the atrium and ventricle.